Panel board unit having renewable fuses



Aug. 18, 1936.

W. H. FRANK ET AL PANEL BOARD UNIT HAVING RENEWABLE FUSES 4 Sheet-Sheet 1 Filed July 18, 1934 INVENTO S,

Aug. 18, 1936. w. H. FRANK El AL 2,051,166

PANEL BOARD UNIT HAVING RENEWABLE FUSES ML 7 43 O 31 I um . 8 m lllllln. mm

ID "L0 K] INVENTORS wow. JK 2% ATTORNEY.

Aug. 18, 1936.

W. H. FRANK ET AL PANEL BOARD UNIT HAVING RENEWABLE FUSES Filed July 18, 1934 4 Sheets-Sheet 3 III . 1NVENTOR5. WM fl. 2M1.

Q 3 jfiamg ATTORNEY.

Aug. 18, 1936. w. H. FRANK E AL 2,051,166

PANEL BOARD UNIT HAVING RENEWABLE FUSES Filed July 18, 1934 4 Sheets-Sheet 4 ATTORNEY.

Patented Aug. 18, 1936 PATENT OFFICE PANEL BOARD UNIT HAVING RENEWABLE FUSES William H. Frank,

rison J. L. Frank,

Joseph A. Messing, and Bar- Detroit, Mich, assignors 'to Bulldog Electric Products Company, Detroit,

Mich, a corporation of West Virginia Application July 18, 1934, Serial No. 735,744

10 Claims.

This invention relates to a sectional panelboard made up of units in which branch circuit control switches are combined with fuses form-' ing protective devices, for those circuits. 7

Panelboards of this character are well known in the art. In each known case, however, the fuses of the units'are of the conventional plug or cartridge fuse type, requiring replacement of fuses whenever a fuse blows, In the panelboard of the present invention, the fuses are of the multi-fuse renewable type shown in application Serial No. 666,786, April 19, 1934, which ma tured into Patent No. 2,000,016, of May 7, 1935; consequently, whenever a fuse blows", fuse renewal can be accomplished quickly, easily, and inexpensively, replacement of a multiple fuse wheel not being effected until all the fuses thereof have been blown, and not until after many fuse renewals.

An object of this invention, therefore, is a unit provided with a multiple fuse device and equipped with a circuit-control switch whereby a blown fuse can be replaced by a fresh one without disturbing the panelboard arrangements; that is, a new fuse can be put into the circuit to. replace vthe blown fuse by a simple operation which can be performed from the front of the panelboard. To attain this result there is constructed a mechanism whereby the above result can be attained through manipulation of the handle of the circuit control switch of the unit. The handle of the circuit control switch, therefore, has a dual function, firstly to control the electrical circuits under normal conditions, and secondlyto enable the operator to place a new fuse in the branch circuit when the switch handle is operated.

Another object of the invention is the provision of a switch and fuse unit which can be conveniently opened for replacements and repairs, but only when the switch is in off" position. When the switch is' in "on" position the invention provides an interlock means to look a cover thereto open it and gain access to the fuses therein. When the switch cover canbe opened, the parts therein which are exposed are completely segregated from the live parts by the fact that the etc.

A further object of the invention is the provision of a switch and renewable 'fuse device, which allows frequent fuse renewal with the maximum of in unit closing position so that it is lmpomble switch is open, with the result that there is no danger to the operator from electrical shocks,

of convenience, without tampering with the switch parts for the renewal of blown" fuses.

A further object of the invention is to construct a control switch suitable for cooperating with a multi-fuse wheel of the type shown in our 5 application Serial No. 666,786, April 19, 1934, now Patent No. 2,000,016, of which thisapplication' is a continuation in part, so that the latter can be conveniently mounted for replacement, and at the same time devise a mechanism to shift the 10 fuse wheel for fuse renewal.

Further objects of the invention will be apparent from the description and claims following.

An embodiment of the invention will be described in the following specification. The novel 15 features, particularly pointed out in the appended claims, will be illustrated in, the accompanying drawings forming a part of the specification. In these drawings,

Figure 1 is a'plan view of a double branch 20 single pole panelboard unit, showing the cooperating bus bars in phantom; V

Figure 2 is an elevation, showing one of the four covers of the unit in raised position for fuse wheel replacement; 25

Figure 3 shows a latch detail in section, taken along the line 3-4 of Figure 2;

Figure 4 is a partial section along the line 4-4 of Figure '1, showing the internal construction of a unit of the invention, with the switch in if" 30 position;

Figure 5 is a similar view, but showing the switch in "on" position; g

Figure 61s an elevation of a cover and fuse wheel assembly, shown with details of the locking 35 spring construction; a 7

Figures 7 and 8 are elevation and plan views, respectively, of the locking-spring shown in Figure 6; I

Figures 9 and 10 are sections along line 8-! of Figure 6; Figure 9 shows the switch handle in released position for normal switching operation, and Figure 10 shows the handle in depressed position for changing the position of the fuse wheel for fuse renewal;

Figure 11 is a section along the line ll-l| of Figure 6,- showing-the locking-sprint construc tion;

Flgure 12 is a partial l2-l2 of Figure 4, showing parts of the unit; I

Figure 13 is a partial bottom plan view of the unit, showingthe bus bars in phantom:

Figure 14 is a section alongthe line 14-10 of Figure 4? t section along the line contact and baifle Figure 15 is an enlarged detail of the axle arrangement of the fuse wheel.

The unit smooth sides, ends, central parts therein, which divide the unit into two open-top branches, two covers for each branch, hinged to the central parts, and each carrying a switch and fuse wheel assembly. Thus, there are four separate switches, and these control the four separate branch leads. The supply bars ill are shown in phantom, and the branch leads I I are shown as leading ofi from the ends of the unit. The arrangement shown provides for each lead, between a bus bar l0 and the lead, a switching mechanism, and a fuse protective device. In Figure 1, the upper two switches are shown in on" position, while the lower two are shown in off position.

On top of the unit is a supporting plate l3 which is fastened to the central rigid structure therebeneath by means of screws l4. On the side edges of the plate I 3 are hinges 15 which mount covers 16, each in turn supporting an assembly of a switch and a fuse wheel H; the hinges allow the covers to be raised or opened, as shown in Figure 2, so that the fuse wheels l1 are exposed to view, allowing free manual manipulation thereof for fuse wheel replacement, etc., or to be lowered, to close the interior of the unit.

The fuse wheel itself forms the basis of application Serial No. 666,786, which matured into Patent No. 2,000,016, of May 7, 1935, and is there described in detail. For the purposes of this case it is sufiicient to say that the fuse wheel may be considered as a flat, centrally apertured disc having on its opposite sides spaced bosses H on which lie terminal parts of metal fuses having their fusible portions within the wheel. The terminal'parts of the fuses are engaged by stationary contacts of the unit to bridge them and complete the circuits through the units from the bus bars l0 to the branch leads I I. The bosses are circularly spaced and in effect form ratchet teeth for the wheel, to be picked up by pawl-like moving and indexing parts of the switches of the unit,

whereby the wheels may be given intermittent rotation for fuse renewal and properly indexed for contact making. I s

The covers l6 are held in closed position, as shown in Figures 1 and 2, by means of a latch 2|,

va detail view 'of which is Figure 3. In general the latch comprises'a U shaped spring member 2|,

held in firm position by a screw. 0n the upper ends, which l6, nibs 2Ia are formed, and these'engage the upper surfaces of the covers l6 and prevent them' from being raised. The, ends of the latch2l be squeezed together to move nibs the covers to be raised or opened.

may

There are provided, in the supporting plate I3, I

windows 22 for observation. of indicating legend on a cardwhich may. be placed on the rigidv v which is fastened a small plate 26 supported from the cover by means of rivets 21. This plate 26 conforms in contour to the curved surface of the cover, and is provided with an observation holepass, through apertures Ilia; in covers,

2 la and permit free manipulation of the handle 24 of the switch and is of sufficient length to allow the handle 24 to move to and from off and on positions.

The switch Referring to Figure 4, there is found a crosssectional view of a switch showing the handle 24 in its off position. Supporting plate i3 is here clearly shown attached to the rigid support means 32 by means of screws l4, which are threaded into the upper member of the rigid support means 32. On the left side of the plate I3 in this figure is shown the hinge l5, which attaches the cover IE to the supporting plate I3. Through the elongated. slot 23 is projected the lower portion 33 of the handle 24, which is attached to the main portion 34 of the switch lever or hell crank, the latter being pivoted on the axle 35, The axle 35 is journalled in the depending portions 36 of the cover iii of the switch, allowing movement of the bell crank thereabout from off position as shown in Figure 4, to on position as shown in Figure 5. On the right side of the main portion 34 of the switch bell crank an car 40 is found, to which is attached by means of a rivet 4| the connecting link 42 which places the switch lever 34 in operable relation with the switching device whose operating arm is referenced 44. With this arrangement it is obvious that when the switch lever 34 is moved from the position shown in Figure 4 to that shown in Figure 5 it will move the arm 44 in relatively the same distance. This will accomplish the shifting of the depending switch contact arm 45 provided with contact 46 from "01? position as shown in Figure 4 to the on" position as shown in Figure 5 with a sudden snapping motion. The switching device 44-'-45 may be of any desired form, as for example of the form shown at Figures 8-9 of application Serial #503,546, now Patent No. 1,974,154, of September 18, 1934, with parts l52-l54 thereof corresponding to parts turned outwardly-so as to catchin a hook 49 formed from'the rigid supporting base 32. The

purpose of this arrangement is to provide an interlocking mechanism for the cover Hi. It prevents the opening of the cover-to the position shown in Figure 2 when the switch is in "on position as shown in Figure 5. It is clear that when the projecting lug 48 on the lever 41 is in cooperative engagement with hook 49 as shown in Figure 5, it will be impossible to lift the outer end of the cover t6 so asto open the-cover about the hinge I 5. However, when the switch is in 0115 'position. as shown in Figure 4, the lug 48 is clear 'of the hook 49 so that the opening operation is, easily accomplished. This interlocking means gives the operator protection against electrical shocks when he tries to open the cover for repairs, or for replacement of the fuse wheel I 1,

because the cover cannot be lifted from its position while the switch is in on position. It is only when the switch is in oif position, with all the parts electrically dead, that the cover can be lifted as described before. In this way there is points.

provided a highly practical means for preventing dangerous shocks, etc., to the operator.

Fusing device Referring now to Figures 9 and 10, the construction of the fuse-changing device will be described in detail.

The switch handle 24 of the switch is of a unique construction, as will now be described. It has an outer cup-shaped portion (Figure 9) with a closed end which is telescoped over an inner tubular portion 54. As shown in Figure 9, a coiled compression spring 55 is positioned between the upper portion of the handle 24 and the lower closed end lug 55 of the tubular portion 54 to push them apart. The spring acts between the inner surface of the cup-shaped upper piece and the lug 56 formed on the inside of the tubular piece 54. The tubular piece 54 is integral with the main switch lever 34 and is attached thereto by means of the lower portion of the handle 33 and the inwardly turned peripheral lug 58. The outer cup-shaped portion of the handle 24 has a narrow downwardly extending strip 64 which extends through a hole 55 in the inwardly turned peripheral lug 58 on the lever 34. The lower end of the downwardly extending strip 54 has an outwardly turned lug 66 which extends through a radial slot 61 in the switch lever 34. The outer end of the lug 66 is in operable engagement with the ramp 69 on the lock ng spring 10, as clearly shown in Figures 9 and 10. When the upper portion of the handle 24 is pushed downwardly against the action of the spring 55 it will take the position shown in Figure 10. Here is shown clearly how the lug 66 operates upon the ramp 69 of the spring 10, pushing it outwardly as indicated.

It will be noticed in Figure 9 that the lower portion of the strip 64 is capable of being pushed down between the circularly spaced bosses or teeth IT on the fuse wheel H. In the present invention, these teeth are used as teeth of af ratchet wheel, to advance the position of the wheel one set of teeth with reference to fixed contact In Figure 10 is shown the relation between the teeth on the fuse wheel I1 and the lower portion of the strip 64. It will be seen that if the handle is turned with the upper portion of the handle 24 depressed, strip 64 will fit in between teeth on the fuse wheel i1. Hence, if the handle 24, when it is in depressed position as shown in Figure 10 is given a turning moment, it is clear that the toothed fuse wheel I! must turn with it. In this way is provided the necessary turning movement to shift the fuse wheel H from the position shown in Figure 4, in which the contact strip 85 is in electrical contact with the fuse terminal 15" to the position where the fuse terminal 15" will be in electrical contact with the strip 85.

As shown in Figure 9, the fuse wheel I! is journalled on a U shaped axle 35, which is in active engagement'with the depending members 35 of the cover H5. The details of the axle 35 are clearly shown in Figure 15. It is there seen that the end portions of the U shaped member are bent at right angles to the axis of the axle 35 to form lugs 81. The separate branches of the U shaped axle 35 are fitted into two holes 88 in the right hand depending member 36 of the cover l6, having the strip 89 positioned between the two branches of the axle. The purpose of this is to prevent the axle from becoming detached from the side member 36 and become lost.

' operating. member.

To position the fuse wheel II on the axle 35 as shown in Figure 9 the operator must remove the pin 90 from the bight of the U shaped axle and then pull the axle as far to the right as possible, so as to place the strip 89 in the extreme lower portion of the bight of the U axle 35. The strip 89 prevents the axle 35 from being removed completely but at the same time gives the operator the opportunity of placing the central hole of the fuse wheel I! in alignment with the axis of the axle 35 so that it will be a simple matter to push the latter through the central hole of the fuse wheel I! and to journal the axle in the left hand depending piece 36. When the bight of the axle extends beyond the outer surface of the side member 36, it is a simple matter to slip the pin 90 into position to hold all the parts in operable position. o

It will be noticed in Figure 15 that the switch lever 34 has an outwardly extending tubular portion 92 which forms a bearing for the axle 35.

At the same time the portion 92 is journalled in the left hand depending piece 36 of the cover l6 so that the switch lever 34 can be operated even though the axle 35 is not in position. Clearly then, even. though the fuse wheel is not in position the switch can be operated from and to off" and on positions.

It will also be observed that the tooth which is picked up by the switch handle, for fuse wheel rotation, is not. adjacent the tooth which is contacted by contact 85 and therefore energized or live, but is as far from that tooth as is possible, namely diametrically opposite, and this insures safe operation of the handle 24 for fuse renewal.

The locking mechanism Returning to the locking spring 10 with its inclined ramp 69, a locking mechanism will be described which utilizes this spring as its principal The details of the spring are clearly shown in Figures 7 and 8. Referring to these figures, there is seen a small upwardly extending nib H0 whose function will be described later. On the right end of the spring 10 is an upwardly extending lug III which is in active engagement with a tooth of the fuse wheel H, as is shown in Figure 6, to lock the wheel in position when the switch and fuse wheel are in normal operating position. As shown further in Figure 6 the spring 10 is attached to the inner side of the depending side portion 36 by means of two rivets 2. from unusual stresses by means of an inwardly extending lug I I 3 from the side member 36. Further, the spring 10 is supported from unusual upper thrusts by an inwardly extending lug l l3a The lower side of the spring 10 is supported cut from the depending side piece 36, and this lug at the same time acts as a guide for the inclined ramp 69. To prevent the spring Hi from being depressed too far inwardly, there is provided on part 36 an inwardly and downwardly extending lug H4, which also acts as a guide.

As described before, the lug II I is positioned so as to fit between adjacent teeth of the wheel ll to prevent any rotation of the fuse wheel I! about its axle 35 when the spring 10 is in normal position. When, however, rotation of the wheel is desired by an operator, he will depress the upper portion of the handle 24 as shown in FigurelO, with the result before mentioned; that is, the lug 66 will come into active engagement with the inclined ramp 69 of the spring 10 and tend to push it to the left, as in Figure 10. This action the outer end of the spring Till, and removes the lug III out of its place between the teeth of the wheel. At the same time, the lower end of the strip 64 will move into the space between two teeth, as shown in Figure 10; then, any turning moment on the handle will be directly transmitted from the handle 24 to the fuse wheel II. This will accomplish the result pointed out before; that is, it will shift the fuse wheel about its axis and place into engagement with the contacting strips 85 a new tooth which automatically places a new fuse into the circuit.

In order to prevent the upper portion of the handle 24 from being depressed when the switch is in on position, there has been provided the nib IIU. When the switch is in the on position shown in Figure 5, nib H0 will be in alignment with the axis of the handle 24, with the result that when the handle is depressed at this point the lug 66 will come into contact with the nib. Immediately. below the nib is found a supporting lug I I3 in the side member 36 which will prevent the spring in from being deformed when force is applied to the upper portion of the handle 24. The result will be that the upper portion of the handle 24 cannot be depressed, and hence cannot come into operable relation between teeth on the fuse wheel ll. This arrangement makes the switch inoperable to move the wheel when the switch ison on position, and hence prevents the switch from moving the fuse wheel backward.

It will be observed that the lug I ll of the locking spring properly indexes the wheel and insures a whole tooth, and no more or less than that, being in contact with the contact 85. This prevents improper contact between contact 85 and a fuse, as well as preventing contact between contact 85 and more than one fuse.

It will also be observed that fuse renewal is accomplished only when the switch is in off position, that the action of fuse renewal automatically causes the switch to arrive at on position, and that the contact 85 is picked up by a fuse before the switch contact arm 45 arrives at its contact making position, Figure 4, to close the circuit through the fuse engaging contact 85. These characteristics enhance the life of the contacts 85, so necessary to proper circuit protection, by eliminating the possibility of arcing at contact 85, insure good contact to the fuse wheel fuses, and also combine the operations of fuse renewal and circuit closing so that they can be performed with one movement of handle 24.

The circuit Referring to Figure 12, there is shown the electrical connections of the switch. The spring contact 85, which is in electrical contact with the wheel fuses, is attached to the base by means of bolt I20 and pin I2I, which extend through the base and the fiat portion 85 of the connecting strip. Attached to the bolt I 20 which extends through the base I3Il is wire I I, which is the lead extending to the controlled circuit. Beginning at this point the circuit is as follows: First, through the contact strip 85 to the fuse terminal 15 on the fuse wheel I7; thence througha fuse incorporated between the terminal 15 and the antipodal terminal 15a; thence to the second contacting strip 85a; thence to contacting strip 851), which is in operable relation with the switch member 45; thence to a central connecting lug 850, which is connected to the bus bar strip I40 by means of bolt I4I.

Returning to the contact strip 85a, the same is supported by a spring member I42 to give the contacting strip 85a greater resiliency. The spring member I 42 is attached to the contact strip by means of rivets I43, it being so arranged that 5 only the outer end of the member I42 exerts its force at the point where the contacting strip 85a makes electrical contact with the terminal 15a.

Referring to Figure 12, there are provided 10 proper insulation baffles I56 to give the necessary electrical protection to prevent fiashovers, etc.

Now having described the invention and a preferred embodiment thereof, it is to be understood that the said invention is to be limited, not to 15 the specific details herein set forth, but only by the scope of the claims which follow.

What we claim is:

1. A multiple fuse and switch device comprising a movably mounted multiple fuse element, and a handled switch normally disconnected from and movable for normal switching without causing movement of the fuse element, and means optionally operable to create an operative connection between the switch handle and the multiple fuse 25 element whereby the former may be manipulated to effect fuse renewal movement of the latter.

2. A multiple fuse and switch device comprising a movably mounted multiple fuse element, and a handled switch normally disconnected from and 30 movable for normal switching without causing movement of the fuse element, and means optionally operable to create an operative connection between the switch handle and the multiple fuse element whereby the former may be manipulated 35 to effect fuse renewal movement of the latter, the switch and the multiple fuse element being contained within a body closed by a movable cover, the multiple fuse element being movably and removably mounted on the cover so that opening 40 movement of the cover exposes the multiple fuse element for removal.

3. A multiple fuse and switch device comprising a movably mounted multiple fuse element,, and a handled switch normally disconnected from 45 and movable for normal switching without causing movement of the fuse element, and means optionally operable to create an operative connec-- tion between the switch handle and the multiple fuse element whereby the former may be manipulated to effect fuse renewal movement of the latter, the switch and the multiple fuse element being contained within a body closed by a movable cover, the multiple fuse element being movably and removably mounted on the cover so that opening movement of the cover exposes the multiple fuse element for removal, the cover being interlocked to the switch so as to be. openable only when the switch is in off position.

4. A multiple fuse and switch device comprising a movably mounted multiple fuse element, and a handled switch normally disconnected from and movable for normal switching without causing movement of the fuse element, and means optionally operable to create an operative connection between the switch handle and the multiple fuse element whereby the former may be manipulated to effect fuse renewal movement of the latter when moved from off to on position.

5. In combination, a switch having an accessible handle movable to and from -on and off positions in opposite directions, and a renewable 'multiple fuse element normally out of operative connection with the switch handle, and means optionally manipulable for connecting the switch handle to the element whereby movement of the handle will cause movement of the element for fuse renewal.

6. A multiple fuse device comprising a body closed by a movable cover which mounts therein an externally handled switch and a movably and removably mounted multiple fuse element, and means connecting the switch handle to the multiple fuse element whereby the former may be manipulated to effect fuse renewal, the cover being movable to expose said fuse element for replacement.

7. A multiple fuse device comprising a body closed by a movable cover which mounts therein an externally handled switch and a movably and removably mounted multiple fuse element, and means connecting the switch handle to the multiple fuse element whereby the former may be manipulated to effect fuse renewal, the cover being movable to expose said fuse element for replacement but only when the switch is in off position.

8. A multiple fuse device comprising a body containing a removable multiple fuse element and closed by a movable cover which may be opened to expose the element for replacement, and a switch normally operable independently of the element for controlling the circuit line through the element, the cover and the switch having an interlocked arrangement whereby the cover may not be opened when the switch is closed and the 1 switch may not be closed when the cover is open,

and whereby the switch when the cover is closed,

may be manipulated and when an optionally operable connection is created between the switch and the element to effect fuse renewal movement of the element.

9. A multiple fuse device comprising a body containing a removable multiple fuse element and 5 closed by a movable cover which may be opened to expose the element for replacement, and a switch normally operable independently of the element for controlling the circuit line through the element, the cover and the switch having an interlocked arrangement whereby the cover may not be opened when the switch is closed and the switch may not be closed when the cover is open, and whereby the switch may be manipulated when the cover is closed and a fuse has blown, and 15 when an optionally operable connection is created between the switch and the element, to close the circuit, if open, and simultaneously efiect fuse renewal movement of the element.

10. In combination, a switch having an access- 20 ible handle movable to and from on and off positions in opposite directions, and a renewable multiple fuse element normally out of operative connection with the switch handle, and means optionally manipulable for connecting the switch 25 handle to the element whereby movement of the handle will cause movement of the element for fuse renewal, and means for preventing movement of the element in any but a proper direction regardless of the direction of movement of the switch handle.

WILLIAM H. FRANK. JOSEPH A. NIESSING. HARRISQN J. L. FRANK. 

